1. Field of the Invention
The present invention relates to a portable terminal such as a personal digital cellular (PDC), a personal handy-phone system (PHS), a code division multiple access (CDMA), a global system for mobile communication (GSM), a personal digital assistants (PDA) having a datebook size, or a portable personal computer. More particularly, the present invention relates to a portable terminal in which one casing is coupled to another casing via a rotating mechanism at their ends.
2. Description of the Related Art
Various portable terminals are currently manufactured, such as a PDC, a PHS, a CDMA, a GSM, a wide band CDMA (WCDMA) under development as a next-generation technology, a portable phone with CDMA2000 or other communication means, a PDA having a datebook size, or a portable personal computer. These types of portable terminals, having a foldable mechanism superposing one casing on the other casing for increased portability, have become popular. Among them, for example, there has been suggested a portable terminal wherein one casing having a display unit is connected to the other casing having an operation unit via a coupling unit and wherein the casings may be opened or closed with the face having the display unit of one casing directed in the same direction as the face having the operation unit of the other casing.
For example, in Japanese Unexamined Patent Publication (Kokai) No. Hei7-288860 (1995), as shown in FIG. 25(A) and 25(B), there has been disclosed a portable terminal 200, comprising one casing 201 having a display unit 207 and a speaker 208 coupled to the second casing 203 having an operation unit 206 and a microphone 205 via a hinge axis unit 204, wherein one casing 201 is rotated horizontally to a face 203a having the operation unit 206 and the microphone 205 of the second casing 203 in a condition that a face 202 having the display unit 207 and the speaker 208 of one casing 201 is directed in the same direction as for the face 203a having the operation unit 206 and the speaker 205 of the second casing 203. An antenna 209 is disposed so as to be retractable at an end of one casing 201.
Also, in Japanese Unexamined Patent Publication (Kokai) No. 2002-158758, as shown in FIG. 26(A) and 26(B), there has been disclosed a portable terminal 210, comprising one casing 211 having a display unit 222 and a speaker 223 and the other casing 215 having an operation unit 221 and a microphone 220. There is provided an inclined face 217 protruding from a face 216 having the operation unit 221 and the microphone 220 of the second casing 215 when the first casing 211 and the second casing 215 are oppositely disposed so that a face 213 having the display unit 222 and the speaker 223 of the first casing 211 is directed in the same direction as for the face 216 having the operation unit 221 and the microphone 220 of the second casing 215. There is also provided an inclined face 214 notched so as to correspond to the inclined face 217 on an opposite face 212 to the face 213 having the display unit 222 and the speaker 223 of the first casing 211. The inclined face 214 is coupled to the inclined face 217 via a rotating shaft 219, and the first casing 211 is rotated relative to the second casing 215 around the rotating shaft 219. An antenna 224 is disposed at an end of the second casing 215.
Both the portable terminals 100 and 210 shown in FIGS. 25(A) and 25(B) and FIGS. 26(A) and 26(B) are capable of displaying information on the display units 207 and 222 when they are closed as shown in FIG. 25(B) and not just when they are opened as shown in FIG. 25(A) and FIG. 26(A), respectively.
The portable terminal 200 shown in FIGS. 25(A) and 25(B), however, is such that the casing 201 rotates parallel to the face 203a having the operation unit 206 and the microphone 205 of the second casing 203. Therefore, the first casing 201 slides on the operation unit 206 of the second casing 203 and keystop symbols on the top face of the operation unit 206 are thereby rubbed by the first casing 201. The keystop symbols may therefore become unreadable and the face opposed to the speaker 208 of the first casing 201 may also be damaged by a flaw or dirt.
Furthermore, due to the first casing 201 rotating parallel to the face 203a having the operation unit 206 and the microphone 205 of the second casing 203, the face 203a having the operation unit 206 and the microphone 205 of the second casing 203 is disposed in parallel to the face 202 having the display unit 207 and the speaker 208 of the first casing 201 when this casing 201 is opened relative to the second casing 203. The face 203a is disposed at the rear of the face 202 having the display unit 207 and the speaker 208 of the first casing 201. Thus the terminal is incapable of bringing the microphone 205 of the second casing 203 close to a user's mouth when the user bends his or her ear to the speaker 208 of the first casing 201 during a phone call, thereby causing a problem of a low sound collecting rate, by which the user cannot transmit clear speech sounds to the other party.
In addition, the portable terminal 210 shown in FIGS. 26(A) and 26(B) also is such that the first casing 211 rotates horizontally to the face 216 having the operation unit 221 and the microphone 220 of the second casing 215 at an initial stage of the rotation. Therefore, the first casing 211 slides on the operation unit 221 of the second casing 215 and thereby keystop symbols on the top face of the operation unit 221 may be rubbed by the first casing 211, making the symbols unreadable and may damage the opposite face to the speaker 223 of the first casing 211 with a flaw or dirt.